The invention relates to an injection molding machine used for processing the plastics, rubber, and other polymeric materials, in particular to an electrically-driven injection molding machine, and specifically to an electrically-driven injection molding system with a dual-driving function and an injection molding method realized using the system, in which both the plasticizing and injection units shares the same set of electrically-driven apparatus.
For a long time, the injection molding machines used for processing the polymers are generally driven by hydraulic systems, that is, the plasticizing unit, injection unit, clamping unit, and so on, are hydraulically driven. During recent years, the electrically-driven injection molding machines have been developed rapidly. Compared with the hydraulically-driven injection molding machines, the electrically-driven injection molding machines have some advantages, including higher control accuracy and response speed to the injection pressure and speed, lower energy consumption and noise. The plasticizing and injection units in the available electrically-driven injection molding machines are, however, generally driven by a set of separate electric transmission apparatus via synchronous belts (as shown in FIG. 1). The available electrically-driven injection molding machines have following shortcomings: (1) One set of electric transmission apparatus is used to drive the plasticizing unit via synchronous belts, the other set of electric transmission apparatus is used to drive the injection unit via synchronous belts, this results in a large and complex structure and increases the manufacturing cost; (2) The transmission accuracy is lower due to indirect transmission via the synchronous belts; (3) The frequent start and stop of the servo-motors result in their heating and so decrease their service life, whereas the frequent start and stop of the ball screws result in the impact force and so speed up their wear.